\\[-1.8ex] Soil Heterogeneity & $-$0.479$^{***}$ & $-$0.445$^{***}$ & $-$0.462$^{***}$ & $-$0.474$^{***}$ & $-$0.479$^{***}$ & $-$0.475$^{***}$ & $-$0.469$^{***}$ \\ 
  & (0.137) & (0.142) & (0.137) & (0.136) & (0.138) & (0.141) & (0.144) \\ 
\\[-1.8ex]
Observations & 19,881 & 19,881 & 19,881 & 19,881 & 19,881 & 19,881 & 19,881 \\ 
R$^{2}$ & 0.407 & 0.406 & 0.407 & 0.407 & 0.407 & 0.407 & 0.406 \\ 
